Seyn Marana is a human Imperial intelligence agent and a founding member of Inferno Squad, introduced in Christie Golden's Battlefront II: Inferno Squad (Del Rey, 2017). She had an eidetic memory and fluency in twenty-nine languages, graduated early from the Imperial Academy of Uyter, and was recruited into the new unit by Admiral Garrick Versio in 0 BBY.
Inside the Dreamers partisan cell she posed as an enslaved forgery specialist. On the Anukara mission she delayed an explosive charge to let civilian children get clear — a decision straightforwardly against her orders — and her cover collapsed shortly afterwards when she revealed a fluency in Chadra-Fan her false identity could not account for. Facing interrogation, she impaled herself on a vibroblade rather than compromise the squad, and her death let the operation finish. She is the novel's argument that the Empire's best people were the ones it could least afford.
Catalogue entry. This figure has a verified record here rather than a full write-up — the encyclopedia labels its own depth instead of padding it.